A molecular and immunologic study of human cytomegalovirus (CMV) proteins is proposed. A new crossed immunoelectrophoretic technique will be used which couples a first dimension SDS polyacrylamide gel electrophoretic separation with a second dimension immunoelectrophoresis in agarose which contains antibody. CMV proteins will first be characterized by electrophoretic mobility, by temporal pattern of synthesis, and by post-translational modifications. The characterized proteins will then be tested with the new immunoelectrophoretic technique against antisera from individuals with CMV-induced disease. This test will identify specific proteins of immunologic importance to the human host. Moreover, different CMV strains will be studied in the same way to identify proteins which vary in electrophoretic mobility among the strains to determine the extent of heterogeneity of CMV in nature. Since diagnosis of CMV disease depends heavily on serologic tests, a clear understanding of the host immune response to CMV specific proteins is imperative.